High tension spark ignition apparatus



June 26, 1945. 1 a. HULBERT EIAL I l H H TENSION SPARK IGNITIONAPPARATUS 5 Sheets-Sheet l Filed May 7, 1945 ||l llL war t ng? 77. v. KII d-D 1.

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June 26, 1945.

1. J. HULBERT ET'AL 2,379,004

HIGH TENSION SPARK IGNITION APPARATUS 5 Sheets-Sheet 3 Filed May 7, 1945fjz/vezz/iors' 1.11224Zfi' Patented June 26-, 1945 HIGH' TENSION SPARKIGNITION APPARATUS Ivan Jack Hulbert and Percy Tatlow, WillesdenJunction, London, England, assignors to Rotax Limited, WillesdenJunction, London, England Application May 7,1943, Serial No. 486,095

In Great Britain May 18, 1942 mm. (or. 171-209) This invention relatesto high tension spark ignition apparatus for internal combustionenglass. The object of the invention is to provide an improveddistributor for use with a magneto or ignition coil.

In the accompanying sheets of explanatory drawings, Figures 1 and 2 arepart sectional side elevations taken at right angles to each other, andFigure 3 is a plan (with the upper cover re moved), of a magnetoembodying the invention.

In carrying the invention into effect as shown, we employ a hollow metalhousing a which is wholly or partly closed, at its lower or inner endandopen at its upper or outer end. To the open end is attached aremovable cover I), this being adapted to contain the high tensioncables as c to be attached to the distributor stator (hereinafterdescribed). The cover 2) may be provided with terminal blocks d for theconnection thereto of the cables leading to the sparking plugs of theengine. The portion a of the housing a immediately adjacent to the coverb is of cylindrical form, and merges into the main portion of thehousing, this main portion having a pair of parallel transverse walls awhich terminate at their ends in arcuate walls a of the same curvatureas the cylindrical portion of the housing. The chamber formed by thehousing a serves to accommodate the distributor.

The distributor comprises a rotor e in the form or one or more blocks ofinsulating material mounted on a spindle ,f, the latter being supportedby bearings g in the housing a so that the axis of the rotor extendsacross the housing. One of the bearings g is mounted in one of thetransverse walls a above-mentioned, and the other ismounted in the innerend of a short hollow cylindrical member i fitting an opening in theother of the said transverse walls, the outer end of the hollow memberbeing closed by a removable cover a. The hollow member 2 and end coveri'orm a chamber into which the adjacent end ,Of the spindle 1 extends,and which accommodates an interrupter associated with a spark generatingwinding or windings k hereinafter described, the interrupter beingformed by a cam 11 on the said end of the spindle, and any. convenientcontact mechanism (not shown) operable by the cam. The distributorstator comprises two or more insulating parts 0, p adapted to embracethe rotor and to be mounted within the housing. The part '0 comprises ablock which is situated in the lower or inner part of thehousing a andis provided with one or a pair of input electrodes q in the and isprovided with a plurality of separate outform or a segmental metal stripor strips adapted to be connected to the high tension winding orwindings of the spark generator. This bloclr is accurately located inthe housing a by a short central spigot T which enters a correspondingsocket s in the housing. Alternatively any other equivalent locatingmeans such as one or more dowels may be used. The two ends of this part0 of the stator rest on shoulders t in the housing a, and are secured tothe shoulders by screws as u. Theother part p of the stator may comprisea single block or a pair of blocks situated side by side in the upper orouter part of the housing a,

put electrodes 0 adapted to be connected to the high tension cables as cleading to the sparking plugs or to the terminal blocks d. This part pof the distributor is formed with a pair of parallel sides toterminating in arcuate ends a: which for ashort distance from the upperor outer face of the said part are adapted to fit closely thecylindrical open end portion a of the housing 0:. Securing of the statorpart p is effected by nuts and studs 3 extending through holes in bothstator parts p, 0 into the shoulders t above-mentioned.

uWhen a large number of sparks are required in each rotation of therotor e, theupper or outer part p of the stator is provided with acorrespondingnumber of output electrodes 1) arranged in for example fourparallel groups, and the rotor is then provided with two connectingelectrodes 2 each of which is cranked as shown in Figure 1 so thatduring one halfa revolution one end co-'- operates with one group ofoutput electrodes and during the other half revolution the other endcooperates with the adjacent group.

A distributor as above described may be used in conjunction with aseparate and independently arranged ignition coil or coils. When it isreone end of themagneto-rotor spindle. Within' the housing a arearranged the usual pole pieces 6 and in association with. these arearranged the generating windings k, of which there may be Themagneto-rotor spindle 3 is situated two, these being situated in thehousing at onposite sides or the magneto rotor 2.

By this invention we are able to provide in a simple and compact form adistributor, or combined distributor and magneto especially adapted foruse on aircraft engines in which a large number of sparks are requiredin each rotation of the distributor rotor, and in which complete metalenclosure is required. Moreover we are able to provide easyaccessibility to all the internal parts, The invention is not, however,limited to the example described as subordinate details may be varied tosuit requirements.

Having thus described our invention what we claim as new and desire tosecure by Letters Patent is:

A spark ignition distributor comprising the combination of a metalchamber having its interior shaped at least in part to a'cylindricalshapeta distributor rotor having its axis extending transversely acrossthe chamber, and a distributor stator arranged within the chamber andconsisting of two parts which embrace opposite sides of the rotor,'oneof the said parts having a locating connection with and adjacent part 01the chamber, and the other stator part having arcuate end surfaces whichserve by contact with the cylindrical inner surface of the chamber tolocate the last'mentioned stator part within the chamber.

IVAN JACK HULBERT. I PERCY TA'ILOW.

